Flags enums are not serialized when multiple flags are set

Hi,

I’ve encountered an issue with Flags enums. When multiple flags are set the enum value is serialized as null. Works fine with only one flag.

Code to repro:

        [Test]
        public void FlagsEnumSerializationWorks()
        {
            var config = new ConfigurationContainer();
            var serializer = config.Create();
            
            var input = new FlagsEnumContainer(LogMessageSeverity.Debug | LogMessageSeverity.Informational);
            var clone = Clone(input, serializer);

            Assert.AreEqual(input.Value, clone.Value);
        }

        public class FlagsEnumContainer
        {
            public LogMessageSeverity Value { get; set; }

            public FlagsEnumContainer()
            {
            }

            public FlagsEnumContainer(LogMessageSeverity value)
            {
                Value = value;
            }
        }

        public enum LogMessageSeverity
        {
            Debug = 0b1, 
            Informational = 0b10, 
            Critical = 0b100
        }

        public T Clone<T>(T objectToClone, IExtendedXmlSerializer serializer)
        {
            using var stream = new MemoryStream();
            serializer.Serialize(stream, objectToClone);
            stream.Seek(0, SeekOrigin.Begin);
            return serializer.Deserialize<T>(stream);
        }

Given the above example, the code:

var input = new FlagsEnumContainer(LogMessageSeverity.Debug | LogMessageSeverity.Informational);
string serialized = serializer.Serialize(new XmlWriterSettings {Indent = true}, input);

produces incorrectly

<?xml version="1.0" encoding="utf-8"?>
<SerializationTests-FlagsEnumContainer xmlns="clr-namespace:AutoSliceAndView.Core.Tests;assembly=AutoSliceAndView.Core.Tests">
  <Value xsi:nil="true" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" />
</SerializationTests-FlagsEnumContainer>

while this snippet works

var input = new FlagsEnumContainer(LogMessageSeverity.Debug);
string serialized = serializer.Serialize(new XmlWriterSettings {Indent = true}, input);

<?xml version="1.0" encoding="utf-8"?>
<SerializationTests-FlagsEnumContainer xmlns="clr-namespace:AutoSliceAndView.Core.Tests;assembly=AutoSliceAndView.Core.Tests">
  <Value>Debug</Value>
</SerializationTests-FlagsEnumContainer>

[jhranac]

Yup, this works! Thanks for the quick fix.

[Mike-E-angelo]

Weird @jhranac it would seem there’s something wrong with the versioning here. The callstack points to a converter class that was in the first release but removed in the 2nd release yesterday.

I have created a new release with a passing test on an uint enumeration type. You can find that here: https://github.com/ExtendedXmlSerializer/home/pull/387#issuecomment-617018114

Let’s see if that treats you better. ✌